Panel lock

ABSTRACT

A panel lock is provided for securing two paperboard panels in face contact. A notch is provided in the edge of one of the panels, and a generally T-shaped locking tongue is hinged to the other panel along a fold line substantially coinciding with the base of the notch. The locking tongue is folded through the notch so that the cross-bar of the T-shaped tongue lies against the surface of the notched panel most remote from the panel supporting the tongue.

United States Patent Isakson [151 3,682,369 [4 1 Aug. 8, 1972 [54] PANELLOCK [72] Inventor: Eugene H. Isakson, Saint Paul,

Minn.

[73] Assignee: l-loerner Waldorf Corporation,

Ramsey County, Minn.

[22] Filed: Jan. 5, 1970 [21] Appl. No.: 703

[52] US. Cl ..229/35 [51] Int. Cl. ..B65d 5/26 [58] Field of Search..229/35, 31

[56] References Cited UNITED STATES PATENTS 2,660,363 11/1953 Trickett,Jr. et al. ..229/35 Honighaum ..229/ 35 2,660,364 1 1/1953 Ferguson..229/35 3,246,829 4/1966 Sexton ..229/ 3 1 3,335,935 8/1967 McCallum..2 29/3l Primary Examiner-James B. Marbert Attomey-Robert M. DunningABSTRACT A panel lock is provided for securing two paperboard panels inface contact. A notch is provided in the edge of one of the panels, anda generally T-shaped locking tongue is hinged to the other panel along afold line substantially coinciding with the base of the notch. Thelocking tongue is folded through the notch so that the cross-bar of theT-shaped tongue lies against the surface of the notched panel mostremote from the panel supporting the tongue.

2Claims,8Drawingfigures minnows 1m 3.682.369

sum 2 or 2 47 45 j 5 it? a *:1 HL I 13/ E I I h I 34 i 5/ i [ii 576?- 4342 43 42 39/? r 4 44 I 44 57 55/ 46/) 25,45 [56 L40 IN ENTOR 4f 32 4]Fuss/v5 H. [SAKSON ATTORNEY PANEL LOCK This invention relates to animprovement in comer lock and deals particularly with a means ofsecuring a pair of paperboard panel portions in face contact.

BACKGROUND OF THE INVENTION Various means have been provided forsecuring panels in face contact. For example, paperboard trays ofteninclude a bottom panel, side and end walls hingedly connected to thebottom panel, and comer flaps on certain of the walls which are foldedinto face contact with adjoining walls. The corner flaps may be gluedtogether, or may be stitched or stapled together, but such anarrangement usually requires special equipment and is time consuming,and the resulting trays cannot be disconnected and flattened out if itis so desired.

In order to detachably connect the walls in erected condition, linerpanels have often been hinged to the upper edges of two opposed walls,these linerpanels being folded over the corner flaps on the other panelsand locked in position by a suitable means. Such a means is veryeffective but is of necessity more expensive as the area of thepaperboard used is increased.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide an extremely simple means of locking panels in face contact. Theedge of one of the overlapping panels is provided with a notch, and theedge of the other panel is provided with a generally T-shaped lockingtongue. When the two panels are in face contact, the locking tongue maybe swung down into the notch to lock the two panels from separation.

A feature of the present invention resides in the simplicity of theoperation of setting up a tray or. the like. But providing comer flapson two opposed panels which are foldable into face contact with theremaining two opposed panels, the walls may be locked in proper relationby merely swinging four locking tongues into corresponding notches. Thecomer flaps may be folded either inwardly or outwardly of the adjoiningwalls. The locking tongues may be provided on the comer flaps in whichcase the locking tongues are folded outwardly to project beyond theadjoining wall. Alternatively, the locking tongues may be on the traywall, and the notches may be in the corner flaps so that the tray may belocked by swinging the locking tongues inwardly or outwardly, dependingupon whether the comer flaps are outwardly or inwardly of the adjoiningtray wall.

A feature of the present invention resides in the provision of a meansof holding two panels in face contact which may, if desired, bedisconnected at least a reasonable number of times. The locking tonguesare distorted to some extent in the locking operation and will notfunction effectively if locked and unlocked continuously, but may beunlocked several times if desired.

These and other objects and novel features of the present invention willbe more clearly and fully set forth in the following specification andclaims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a trayin set up form. FIG. 2 is an enlarged perspective view of one of thelocks in locked position.

FIG. 3 is a perspective view of the inside of a portion of the trayshowing one of the locks.

FIG. 4 is a diagrammatic view of the blank from which the tray isfonned.

FIG. 5 is an enlarged detail of the locking notches.

FIG. 6 is a perspective view of a corner of a modified form of a tray.

FIG. 7 is a perspective view of the tray corner shown in FIG. 5 inpartially locked position.

FIG. 8 is a diagrammatic view of the blank from which the modified formof tray is formed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention is shown asapplied to a rectangular tray. Obviously, the tray may form one portionof a telescope container including two tray sections telescopedtogether. Furthermore, the trays could be hexagonal, octagonal, or eventriangular if desired, it only being necessary that the tray structureinclude comer flaps which are folded in face contact with adjoiningpanels.

' The tray A shown in FIGS. 1 to 4 of the drawings is constructed of theblank indicated in FIG. 4. The tray is shown as including a rectangularbottom panel 10 which is foldably connected along parallel fold lines 11to side walls 12. The bottom panel 10 is also connected along parallelfold lines 13 to end walls 14. The side walls 12 are provided as theirend edges with corner flaps 15 which are connected thereto alongparallel fold lines 16, these fold lines 16 being substantiallyextensions of the fold lines 13, but which may be slightly ofisettherefrom in order to allow for the thickness of the paperboard.

The upper edges of the end walls 14 are each provided with a pair ofnotches 17 in the areas thereof which normally overlap the comer flaps15. As is indicated in FIG. 5 of the drawings, each notch 17 has arelatively wide inlet portion 19 connected by inwardly convergingrounded cut lines 20 to a relatively narrower throat portion 21. Belowthe throat, the notch is relatively wider providing a wide base portion22. Each comer flap 15 is provided with a generally T-shaped lockingtongue. Each locking tongue 23 includes a relatively wide end portion 24forming the cross bar of the T, and a relatively narrow stem portion 25,the stem portion 25 preferably being slightly wider than the throat 21of the notch 17, and of substantially the same width as the base portion22 of the notch 17. The cross bar of the T, or the end portion 24 ispreferably wider than the base portion 22 of the notch. The length ofthe stem 25 is substantially the same as the thickness of the paperboardused. Normally the tray is made of corrugated paperboard.

In the arrangement illustrated in FIGS. 1 through 5, the tray is set upby folding the side walls 12 upwardly into parallel relation, andfolding the comer flaps 15 to extend in opposed relation along the foldlines 13, as indicated in FIG. 1. The end walls 14 are then foldedupwardly outwardly of the comer flaps l5, and the locking tongues 23 arefolded downwardly and outwardly through the notches 17. Actually thismay be done by folding the locking tongues downwardly, distortingportions of the tongues to pass through the notches, or the lockingtongue may .be folded outwardly while the side walls are slightly lessthan right angles to the bottom panel, swinging the corner flapsdownwardly into position against the bottom wall as the locking tonguesare inserted.

The finished tray has the locks projecting outwardly therefrom asindicated in FIG. 1. If the tray is a portion of a telescope container,the ends of the tongues are bent down as the cover of the container isinserted. It is possible to arrange the structure so that the lockingtongues of the bottom section project outwardly, and the locking tonguesof the upper section project inwardly, concealing the ends of thetongues when the two sections are engaged.

A modified form of tray B is indicated in FIGS. 6, 7, and 8 of thedrawings. As indicated in FIG. 8, the tray blank includes a rectangularbottom which is foldably connected along parallel fold lines 31 to sidewalls 32. The bottom panel 30 is also connected along parallel foldlines 33 to end walls 34. The end walls 34 are provided with cornerflaps 35 which are connected to the end walls along parallel fold lines36, these fold lines being substantially parallel to the fold lines 31,but offset slightly therefrom to allow for the thickness of thepaperboard.

The edges 37 of the flaps 35 which are upper most in the set up form ofthe tray provided with notches 39 which may be identical to the notches17 illustrated in FIG. 5 of the drawings, and which accordingly will notbe described in detail. The edges 40 of the side walls 32 are providedwith generally T-shaped locking tongues 41 which are positioned toregister with the notches 37 in the corner flaps 35. Each locking tongue41 includes a short stern portion 42 connected to the side wall 32 alonga fold line 43, and connected to the cross bar member 44 along a foldline 45. A pair of generally parallel fold lines 46 extend across thecross bar 44 in substantial alignment with the side edges of the stemportion 42 of the locking tongue. The fold lines 46 form wings whichfold out of the plane of the center portion of the cross bar 44 when thelocking tongues are folded into the notches 39. This operation isillustrated in FIG. 7 of the drawings. It will be noted that in FIG. 7,the corner flaps 35 are folded outwardly of the side walls 32, and thelocking tongues 31 fold outwardly, this arrangement is preferable inview of the fact that the corner flaps then wrap around the comers ofthe side walls and hold the side walls from bulging outwardly. However,if preferred, the corner flaps 35 could be arranged to fold inwardly ofthe side walls in which case the locking tongues 41 would be foldedinwardly rather than outwardly.

I claim:

I. A corrugated paperboard tray including a bottom panel, side panelshinged to the edges of said bottom panel and extending upwardlytherefrom and corner flaps hinged to an end of certain of said sidepanels and folded into face contact with the adjoining side panel, alock including:

a notch in an edge of one of the overlapping panels at each comer ofsaid bottom panel,

a generally T-shaped locking tongue hinged to the other of saidoverlapping panels along a fold line substantially coinciding with thebase of the notch,

said locking tongue including a stern portion having parallel sidesextending through said notch, said st mbei fal et th th thick ssof micorriig ted gg aiz iai df an a ci'oss-bzi r portion engaging the surfaceof said one overlapping panel opposite that engaged by said other panel,and parallel fold lines extending across said crossbar portion from thestem portion to the end of said locking tongue portions, said parallelfold lines being substantially aligned with the parallel sides of saidstem.

2. A corrugated paperboard tray including a bottom panel, side panelshinged to the edges of said bottom panel and extending upwardlytherefrom and corner flaps hinged to an end of certain of said sidepanels and folded into face contact with the adjoining side panel, alock including:

a notch in an edge of one of the overlapping panels at each comer ofsaid bottom panel,

a generally T-shaped locking tongue hinged to the other of saidoverlapping panels along a fold line substantially coinciding with thebase of the notch,

said locking tongue including a stem portion having parallel sidesextending through said notch, said stem being of a length greater thanthe thickness of the corrugated paperboard, and a cross-bar portionengaging the surface of said one overlapping panel opposite that engagedby said other panel, said notch having a base portion substantiallyequal in width to said stem portion of said locking tongue and a throatportion above said base portion which is slightly narrower than thewidth of said stern portion.

1. A corrugated paperboard tray including a bottom panel, side panelshinged to the edges of said bottom panel and extending upwardlytherefrom and corner flaps hinged to an end of certain of said sidepanels and folded into face contact with the adjoining side panel, alock including: a notch in an edge of one of the overlapping panels ateach corner of said bottom panel, a generally T-shaped locking tonguehinged to the other of said overlapping panels along a fold linesubstantially coinciding with the base of the notch, said locking tongueincluding a stem portion having parallel sides extending through saidnotch, said stem being of a length greater than the thickness of thecorrugated paperboard, and a cross-bar portion engaging the surface ofsaid one overlapping panel opposite that engaged by said other panel,and parallel fold lines extending across said cross-bar portion from thestem portion to the end of said locking tongue portions, said parallelfold lines being substantially aligned with the parallel sides of saidstem.
 2. A corrugated paperboard tray including a bottom panel, sidepanels hinged to the edges of said bottom panel and extending upwardlytherefrom and corner flaps hinged to an end of certain of said sidepanels and folded into face contact with the adjoining side panel, alock including: a notch in an edge of one of the overlapping panels ateach corner of said bottom panel, a generally T-shaped locking tonguehinged to the other of said overlapping panels along a fold linesubstantially coinciding with the base of the notch, said locking tongueincluding a stem portion having parallel sides extending through saidnotch, said stem being of a length greater than the thickness of thecorrugated paperboard, and a cross-bar portion engaging the surface ofsaid one overlapping panel opposite that engaged by said other panel,said notch having a base portion substantially equal in width to saidstem portion of Said locking tongue and a throat portion above said baseportion which is slightly narrower than the width of said stem portion.